STERILISATION APPARATUS

Description

[0001] The invention relates to a sterilisation apparatus for medical instruments and the like objects which are easy to handle and/or remove, consisting of a casing with a sterilisation chamber mainly comprising of a double-walled boiler whereby fluid such as demineralised water being present between an inner and outer wall of said boiler and regulators and heating elements for performing the sterilisation process by means of which temperature and steam generated therefrom are controlled.

[0002] The sterilisation apparatus according to the invention concerns a so-called mini-sterilisation apparatus, which is often used in dentists' practices. The content of this type of apparatus is in the range between 10 - 50 litres and the required temperatures often between 121° C - 134°C and pressures of about 210 - 310 Kpa.

[0003] The German patent 904 237 as well as the French patent 889 067 discloses relatively small sterilisation apparatus. However these types of apparatus could not fulfil the present requirements such as high sterilisation temperatures and pressures as indicated above which obviously should safely be realised in a relatively smaller apparatus at least at the dimensions as the cited apparatuses.
Another well known problem relating to the cited mini-sterilisation apparatus is that this type of apparatus can barely, if at all, comply with the (international) requirements which among others relate to obtaining a stable ambient temperature of the sterilisation boiler during sterilisation.

[0004] The sterilisation apparatus according to the invention overcomes these problems due to the fact that the casing with the sterilisation chamber comprises a cylindrical horizontally arranged boiler wherein a cylindrical inner boiler having a volume of 10 - 50 lit. is horizontally placed whereby said fluid partly fills a cylindrical space between said boilers whilst at least during the sterilisation process the upper cylindrical space is filled with steam and means being present for feeding steam pulsatingly into said inner boiler (3).
In order to optimise the sterilisation process in this type of apparatus means, such as ejectors, vacuum valves and the like elements, are applied that according to the invention can provide a pulsating vacuum in said boiler such that air in the instruments or the like objects which are to be sterilised can be effectively removed.

[0005] Advantage is offered by the embodiment according to the invention wherein means are present which can also provide a pulsating vacuum in said boiler such that air in the instruments or the like objects which are to be sterilised can be removed.

[0006] In order to secure the sterilisation process according to the invention means are present for setting, respectively measuring pressure, temperature, time and output for controlling all phases occurring within said boiler before, during and after the sterilisation process. These means are preferably controlled by a process computer which displays various data read-outs digitally and/or alphanumerically and/or graphically e.g. to an internal or external printing apparatus (printer).

[0007] Especially in a dentist's practice where an autoclave will be used intensively it may be desirable to provide a mini sterilisation apparatus with a (time) switch clock for use of "stand-by" purposes, such as for heating-up of and maintaining the temperature of the boiler.

[0008] Advantage is offered by the embodiment of a mini sterilisation apparatus according to the invention which is characterized in that the sterilisation space of the boiler is provided with lateral supports for a number of standard plateaus on which instruments, whether wrapped or not, and/or bandage substances may be placed.

[0009] For effective use it is desirable that in the mini sterilisation apparatus according to the invention the front or feed side of the boiler can be sealed pressure-tight by means of a heat-isolating hinged door provided with an incorporated nut whereby the casing to that end is provided with a swivelable hermetically sealing screw. The screw seal is prefeably operated by means of an electromotor of which the operating phases are run via said process computer.

[0010] In order to comply with the procedure required of process sterilisation, according to the invention preferable use is made of a sterilisation boiler for incorporation in a mini sterilisation apparatus which is characterized in that a cylindrical sterilisation boiler is placed symmetrically though non-concentrically within the cylindrical outer boiler, such that in the use-position the volume of the fluid or water space down in the double-walled boiler is considerably larger than up in the boiler.

[0011] It is advantageous if this sterilisation boiler is provided in a casing in which also the fluid reservoir with corresponding pump, control appendages, a dry-air connection and a connection to a vacuum line with valves being present.

[0012] The invention is hereinafter described by means of examples of embodiments, whereby advantages and other features of the invention will become apparent.

Figure 1 shows a perspective view of a mini sterilisation apparatus;

figure 2 shows a block scheme of the most important operational functions of the sterilisation apparatus;

figure 3 shows, according to a computer drawing, another embodiment of the sterilisation apparatus.

[0013] Figure 1 shows in perspective a front view of the sterilisation apparatus, in fact the casing 1 thereof, which has a mainly rectangular shape and is made of suitable plate material. The front side shows a door 2 which can be swivelled open over more than 120 degrees and which further is well isolated against heat loss. Opening and closing the door occur automatically by activating an electrical operating button (not drawn). The opened door depicts a (inner) boiler 3 of which the space 4 in this embodiment is provided with four bearing plateaus 6, so-called norm trays, on which (wrapped) instruments or bandage substances can be transported. To that end space 4 is provided with supports 5. Door 2, which can seal sterilisation space 4, is fixed pressure-tight in the closed position by an electrically driven screw-seal 7 and cannot be opened during a sterilisation process. During a process the LCD screen 8 graphically displays the course of this process.

[0014] The sterilisation apparatus moreover comprises a process computer of which the control 9 is embodied with an indication for each process phase. The pressure, temperature, sterilisation time, drying time and possible malfunctioning are displayed digitally, eventually supported alphanumerically or graphically. The pressure in the so-called steam generator is, as prescribed, displayed analogously on indicator 10.

[0015] Figure 2 schematically shows the sterilisation boiler 11 with various auxiliary parts and control apparatuses, which parts are described hereinafter.

[0016] It is to be noted that similar references are used for similar parts.

[0017] Boiler 11 according to the invention comprises an inner wall and an outer wall, 3 respectively 12, whereby the contents of the inner boiler range between 10 to 50 litres. Demineralised water (demi-water) 14-added to space 13 of the double boiler wall 3,12- is heated such that steam 16 is produced at the top of the boiler. Heating of the water occurs through heating elements 17,18 which have been provided in boiler space 13. For the provision of water the sterilisation apparatus comprises a water reservoir 19 onto which a floating switch 20 for level control is provided. In this arrangement a feed pump 21 is applied by means of which water down in space 13 of the double boiler wall 3,12 can be supplied. A shutoff valve 22 for pumping water for boiler space 13 is provided in the pump circuit. As already indicated above, heating elements 17,18 are provided at the bottom of boiler 3,12 by means of which the water supplied can be heated, such that steam 16 is formed at the top for the purpose of the sterilisation process. A safety switch 23 with a float embodiment for protection against dry-boiling is provided at the bottom of the boiler. A water level controller 24 is present at the top so that the proper ratio between steam and water is always obtained. The generated steam 16 is supplied pulsatingly from boiler space 13 through a steam valve 25 into the inner boiler 3. Further, there is a temperature measuring device 26 as well as a pressure transmitter within inner boiler 3. A similar transmitter is also provided in the outer boiler 12. In figure 2 the left-hand side depicts the water and steam system and the right-hand side depicts the vacuum system. Thereby a feed line 28 is provided at the top side of the boiler, in which an aeration valve 29 is provided for feeding clean air when a vacuum is prevailing in the boiler. For the sake of certainty a sterile filter 30 provides for clean air when feeding to valve 29.

[0018] According to the invention a vacuum is drawn pulsatingly in the boiler, which is achieved by using a water-ejector system which mainly comprises an ejector 31 connected to a vacuum valve 32 which is connected through a line to inner boiler 3. A cold-water valve 33 is incorporated in the water system of ejector 31 which serves for generating a vacuum through ejector 31. Further a pressure switch 34 for measuring the water pressure is used in the line system, by which water is tapped-off from feed 35.

[0019] The following gives a brief illustration of a sterilisation process at a temperature of 134 degrees C. A process can only start if door 2 is closed, and the process begins with steaming-through whereby valves 25, 33 and 32 are opened. Valves 33 and 32 of the ejector system remain open during steaming-through. Steam valve 25 is thereby regulated at a pressure of 120 kPa within inner boiler 3. During a certain period, about 90 seconds, there is a continuous discharge of steam and air. After this period of 90 seconds steam valve 25 closes and the first vacuum pulse starts. The pulsating course of the process occurs further by successively controlling the valves concerned, the build-up of pressure as well as the time in seconds, so that the sterilisation pressure and temperature are achieved in an effective manner within the stated period. In this example a temperature of 134 degrees C to a maximum of 137 degrees C is achieved in about 15 seconds. Pressure control in the boiler is achieved by a autonomously functioning control process. However, in case during the sterilisation process the temperature and/or the pressure exceeds the maximum set value, the process is automatically broken off.

[0020] After the sterilisation traject drying of the objects present on plateaus 6 takes place by drawing a vacuum. To this end steam valve 25 is shut and cold-water valve 33 as well as vacuum valve 32 are opened, till a pressure of 10 kPa is reached. At this pressure the actual drying time starts, which lasts 5 minutes in this process (134 degrees C). After drying the boiler is aerated to relieve the vacuum. If the drying process is terminated, valves 32 and 33 are shut. When the boiler pressure lies between 95-105 kPa, aeration valve 29 shuts due to which door 2 can be opened and the sterilised objects can be removed from boiler space 4.

[0021] As stated above, the whole process takes place under the control of and monitoring by a computer and the results are displayed by means of a printing device, a so-called printer (not shown).

[0022] Figure 3 depicts another advantageous embodiment according to the invention in which in particular the water reservoir 13 has been enlarged by the positioning of inner boiler 3 relative to outer boiler 12, i.e. that the amount of water at the bottom of boiler 11 is greater than the amount at the top thereof, which may be favourable for certain sterilisation processes in view of the water-steam ratio.

[0023] The invention is not limited to the embodiments as shown and described above, since one can well imagine other arrangements of sterilisation boilers. The feature according to the invention of using a double boiler wall in a relatively small sterilisation apparatus has however resulted in the fact that such a sterilisation apparatus can comply with the highest standards, including international standards.

Claims

1. Sterilisation apparatus for medical instruments and the like objects which are easy to handle and/or remove, consisting of a casing with a sterilisation chamber mainly comprising of a double-walled boiler whereby fluid such as demineralised water being present between an inner and outer wall of said boiler and regulators and heating elements for performing the sterilisation process by means of which temperature and steam generated therefrom are controlled, characterised in that said casing (1) comprises a cylindrical horizontally arranged boiler (11) wherein a cylindrical inner boiler (3) having a volume of 10 to 50 lit. is horizontally placed whereby said fluid (14) partly fills a cylindrical space (13) between said boilers whilst at least during the sterilisation process the upper cylindrical space is filled with steam and means (25) being present for feeding steam pulsatingly into said inner boiler (3).

2. Apparatus according to claim 1, characterised in that means (31-33) are present that can provide a pulsating vacuum in said boiler (3) such that air in the instruments or the like objects which are to be sterilised can be removed.

3. Apparatus according to claim 1 or 2, characterised in that means are present for setting, respectively measuring pressure, temperature, time and output for controlling all phases occurring within said boiler (11) during and after the sterilisation process.

4. Apparatus according to claim 1 - 3, characterised in that said means are controlled by a process computer (8-10) which being able to display various data read-outs digitally and/or alphanumerically and/or graphically, e.g. to an internal or external printing apparatus.

5. Apparatus according to any of the preceding claims, characterized in that a (time) switch clock for use of "stand-by" purposes, such as for heating-up of and maintaining the temperature of said boiler, is avaiable.

6. Apparatus according to any or several of the preceding claims, characterized in that the sterilisation space of the boiler is provided with lateral supports of standard plateaus on which instruments, whether wrapped or not, and/or bandage substances can be placed.

7. Apparatus according to any or several of the preceding claims, characterized in that the front or entrance of the boiler is sealed pressure-tight by means of a heat-isolating hinged door provided with an incorporated nut whereby the casing to that end is provided with a swivelable hermetically sealing screw.

8. Apparatus according to any or several of the preceding claims, characterized in that the screw seal is operated by means of an electromotor of which the operating phases are controlled by said process computer.

9. Apparatus according to any or several of the preceding claims, characterized in that a cylindrical sterilation boiler is placed symmetrically though non-concentrally within said cylindrical outer boiler, such that in the use-position the volume of the fluid or water space down in the double-walled boiler is considerably larger than up in the boiler.

10. Apparatus according to any or several of the preceding claims, characterized in that the process computer and boilers are provided in a casing in which also the fluid reservoir with corresponding pump, control appendages, a dry-air connection and a connection to a vacuum line with valves being present.

Ansprüche

1. Sterilisationsapparat für medizinische Instrumente und ähnliche Gegenstände, die einfach zu handhaben und/oder zu entnehmen sind, der aus einem Gehäuse mit einer Sterilisationskammer besteht, die im wesentlichen einen doppelwandigen Boiler umfasst, wobei Flüssigkeiten wie zum Beispiel entmineralisiertes Wasser zwischen der Innen- und der Außenwand des genannten Boilers vorhanden sind sowie Regler und Heizelemente zur Durchführung des Sterilisationsprozesses, durch welche die Temperatur und der daraus erzeugte Dampf kontrolliert werden, dadurch gekennzeichnet, dass das genannte Gehäuse (1) einen waagerecht angeordneten zylindrischen Boiler (11) umfasst, worin ein zylindrischer innerer Boiler (3) mit einem Volumen zwischen 10 und 50 Litern, waagerecht angeordnet ist, wobei die genannte Flüssigkeit (14) teilweise den zylindrischen Raum (13) zwischen den genannten Boilern ausfüllt, wobei zumindest während des Sterilisationsvorgangs der obere zylindrische Raum mit Dampf und Mitteln (25) ausgefüllt ist, die vorhanden sind, um die stoßweise Dampfzufuhr in den genannten inneren Boiler (3) zu gewährleisten.

2. Apparat gemäß Anspruch 1, gekennzeichnet dadurch, dass Mittel (31-33) vorhanden sind, die ein stoßweises Vakuum in dem genannten Boiler (3) gewährleisten können, so dass die Luft in den Instrumenten oder ähnlichen Gegenständen, die sterilisiert werden sollen, entfernt werden kann.

3. Apparat gemäß Anspruch 1 oder 2, gekennzeichnet dadurch, dass Mittel vorhanden sind, die den Druck, die Temperatur, die Zeit und den Ausstoß einstellen bzw. messen, damit alle in diesem Boiler (11) eintretenden Phasen während und nach dem Sterilisationsvorgang kontrolliert werden können.

4. Apparat gemäß Anspruch 1 - 3, gekennzeichnet dadurch, dass die genannten Mittel durch einen Prozess-Rechner (8-10) kontrolliert werden, der in der Lage ist, die verschiedenen Ausgabedaten digital und/oder alphanumerisch und/oder graphisch anzuzeigen, zum Beispiel auf einem internen oder externen Drucker.

5. Apparat gemäß einem der vorausgegangenen Ansprüche, gekennzeichnet dadurch, dass eine (Zeit-) Schaltuhr zur Verwendung im "Stand-by"-Modus zur Verfügung steht, um zum Beispiel die Temperatur des genannten Boilers zu erhöhen bzw. zu halten.

6. Apparat gemäß einem oder mehreren der vorausgegangenen Ansprüche, gekennzeichnet dadurch, dass der Sterilisationsraum des Boilers mit seitlichen Stützen für Standardtabletts, auf denen die Instrumente, die entweder verpackt oder unverpackt sind, und/oder Bandagiersubstanzen angeordnet werden können.

7. Apparat gemäß einem oder mehreren der vorausgegangenen Ansprüche, gekennzeichnet dadurch, dass die Vorderseite oder der Zugang des Boilers druckdicht versiegelt ist durch eine wärmeisolierende Tür mit Scharnieren, ausgestattet mit eingebauter Mutter, wobei das Gehäuse an diesem Ende mit einer schwenkbaren, hermetisch versiegelnden Schraube ausgestattet ist.

8. Apparat gemäß einem oder mehreren der vorausgegangenen Ansprüche, gekennzeichnet dadurch, dass die Schraubenversiegelung gesteuert wird von einem Elektromotor, deren Betriebsphasen von dem genannten Prozess-Rechner gesteuert werden.

9. Apparat gemäß einem oder mehreren der vorausgegangenen Ansprüche, gekennzeichnet dadurch, dass der zylindrische Sterilisationsboiler symmetrisch jedoch nicht mittig in dem genannten äußeren zylindrischen Boiler angeordnet ist, so dass in der Betriebsposition das Volumen des Raumes für Flüssigkeit oder für das Wasser unten in dem doppelwandigen Boiler wesentlichen größer ist als in dem oberen Boiler.

10. Apparat gemäß einem oder mehreren der vorausgegangenen Ansprüche, gekennzeichnet dadurch, dass der Prozess-Rechner und die Boiler sich in einem Gehäuse befinden, in dem sich auch das Flüssigkeitsreservoir mit der dazugehörigen Pumpe, das Steuerungszubehör, eine Trockenluftverbindung und eine Verbindung zu einer Vakuumleitung mit Ventilen befinden.

Revendications

1. Appareil de stérilisation pour instruments médicaux et autres objets similaires faciles à manipuler et / ou à déplacer, consistant en un coffret avec chambre de stérilisation constituée principalement d'un ballon d'eau chaude à double paroi, un fluide comme de l'eau déminéralisée étant présent entre les parois interne et externe dudit ballon et en des régulateurs et éléments de chauffages permettant de contrôler la température et la vapeur générées par le ballon, et caractérisé en ce que le coffret (1) comprend un ballon d'eau chaude (11) cylindrique disposé horizontalement et comprenant un second ballon d'eau chaude disposé horizontalement, le fluide (14) remplissant partiellement un espace cylindrique (13) d'une capacité de 10 à 50 litres situé entre les deux ballons tandis que, au moins pendant la phase de stérilisation, l'espace cylindrique supérieur est rempli de vapeur et de moyens (25) servant à acheminer la vapeur par pulsations dans le ballon d'eau chaude intérieur (3).

2. Appareil conforme à la revendication 1, caractérisé en ce que des moyens (31-33) capables de produire un vide pulsatif dans ledit ballon (3) de telle sorte que l'air présent dans les instruments ou objets similaires à stériliser puisse être supprimé sont prévus.

3. Appareil conforme à la revendication 1 ou 2, caractérisé en ce que des moyens permettant de définir et mesurer la pression, la température, la durée et le débit en vue de contrôler toutes les phases dudit ballon d'eau chaude (11) pendant et après le processus de stérilisation sont prévus.

4. Appareil conforme aux revendications 1 à 3, caractérisé en ce que lesdits moyens sont contrôlés par un ordinateur industriel (8-10) capable d'afficher de manière numérique, alpha-numérique et / ou graphique plusieurs données, en les transférant par exemple vers une imprimante interne ou externe.

5. Appareil conforme à l'une ou l'autre des revendications précédentes, caractérisé en ce qu'un interrupteur horaire nécessaire pour des situations de 'stand-by' comme pour augmenter et maintenir la température dudit ballon d'eau chaude, est disponible.

6. Appareil conforme à une ou plusieurs des revendications précédentes, caractérisé en ce que l'espace de stérilisation du ballon est équipé de supports latéraux ou plateaux standards sur lesquels des instruments, emballés ou non, et/ou des substances de pansement peuvent être placés.

7. Appareil selon une ou plusieurs des revendications précédentes, caractérisé en ce que l'avant ou l'entrée du ballon est verrouillée de manière hermétique à la pression par une porte pivotante avec écrou incorporé, le coffret étant, lui, équipé d'une vis pivotante de verrouillage hermétique.

8. Appareil conforme à une ou plusieurs des revendications précédentes, caractérisé en ce que le verrouillage par vis est activé à l'aide d'un moteur-électrique dont les phases opérationnelles sont contrôlées par ledit ordinateur industriel.

9. Appareil conforme à une ou plusieurs des revendications précédentes, caractérisé en ce qu'un ballon de stérilisation cylindrique est disposé symétriquement mais de façon non concentrique à l'intérieur dudit ballon cylindrique extérieur, et de telle sorte que en position d'utilisation, le volume de l'espace rempli de fluide ou d'eau situé dans le ballon à double paroi est nettement plus important que celui situé dans le ballon.

10. Appareil conforme à une ou plusieurs des revendications précédentes, caractérisé en ce que l'ordinateur industriel et les ballons sont pourvus d'un coffret comprenant également le réservoir de fluide avec la pompe correspondante, des éléments de contrôle, une connexion à air sec et une connexion vers une ligne sous vide avec valves.

Drawing